Apparatus for removing plaster from plate glass surfacing tables



July 8, 1941. v.1. e. HAWORTH APPARATUS FOR REMOVING PLASTER FROM PLATE GLASS SURFACING TABLES Filed July s 1939 s Sheets-Skeet 1 v Jn'ventor .Q/AME 6. HA WOATH Cmorneg y 1941" J. G. HAWORTH 2,248,232

APPARATUS FOR REMOVING PLASTER FROM PLATE GLASS SURFACING TABLES Filed July 31, 1939 3 Sheets-Sheet 2 Illlh III"! 5 /1111 M71175 VIII/Ill 3nocntor I UAMEO 6 HA wow/1.

Grim-neg July 8, 1941. J. a. HAWORTH APPARATUS FOR REMOVING PLASTER FROM PLATE GLASS SURFACING TABLES Filed July 31, 1939 3 Sheets-Sheet 3 s i v I Zhwemor ojnmza G. HAWOKTH. M

Cttomeg Patented July 8, 1941 UNITED STATES PATENT OFF-ICE APPARATUS FOR REMOVDIG PLASTER FROM PLATE GLASS SURFACING TABLES I Q 7 James G. Haworth, Toledo, Ohio, assignor to Libbey-Owens-Ford Glass Company, Toledo, I hio, acorporation of Ohio Application'July'31, 1939; Serial No. 287,472

" 6 Claims. 01. 15-180) The present invention relates to improvements in apparatus forremoving'plaster from the tops of tables employed in the surfacing of plate glass.

The'glass sheets are ordinarily bedded upon the surfacing tables ina layerof plaster of Paris or the like which securely h oldsthem in place during the grinding and polishing thereof. After the glass has been surfaced and removed from the tables, it is necessary to cut away the old plaster before applyinga new layer. It has been proposed to clean'the'plaster from the tables by using abrading elements consisting 'of sections of wire cable made up of strands of wire twisted together. 7 The use of abrading elements of this character for removing the plaster has been found to be very satisfactory and further that they cut away the plaster without injury to the tables. The subdivision of the abrading elements, due to the plurality of wire strands'whi'ch go to make up each section of'the cable, gives a plurality of cutting pointswhich 'act very eifectively to cut through the layer of plaster upon the tables. One objection to the use of this type'of abrading elements, however, has been the" rapidity with which the cable wears away. This is largely due to the spreading of the strands of wire which results in the breaking thereof and, as a result. of this spreading of the wires; thecutting tips thereof do not always engage the"plaster.' I

Among the objects of this invention is the provision of means for improving the cutting action of the cable sections and for also materially increasing the 'life thereof. I v v v In carryingout'theinvention, there is fitted over each section of wire cable a sleeve preferably formed of rubber, rubber composition. or the like. These sleeves may consist of pieces of ordinary rubber'hose and serve to effectively prevent spreading and breaking. off of the, individual strands of wire. The rubber sleeves in no way interfere with the abrading action of the cable and simply wear away with the cable sections.

Otherobjects and advantages of the invention will become more; apparent. during the course of the following description, when taken in connection with the accompanying drawings.

In the drawings, wherein like numerals are employed to designate. like. parts throughout the same: V

Fig. 1 is a side elevation ofcleaning apparatus constructed in accordance. with the invention;

Fig, 2 is a plan view.thereof;..

Fig. 3 is an end view .of one of the cleaning heads; 7

Fig. '4 is a vertical section taken substantially on line 44 of Fig. 3;

Fig. 5 is a horizontal detail section taken substan-tially on line 5-5 of Fi 4;

Fig. 6 is a view of one of the cable sections showing the rubber sleeves thereon;

Fig. 7' is a similar view showing the cable section and sleeves after they have been worn away; I

Fig. 8 is a plan View of a modified type of cleaning head; and

Fig. 9 is a vertical longitudinal section taken substantially on line 9-9 of Fig. 8.

Referring now to the drawings and particularly to Figs. 1 to 5inclusive, l0 designates one of a series of surfacing tables which-are adapted to be arranged end to end and movable in a definite, substantiallyhorizontal path tocarry glass sheets mounted thereupon, first beneath a series of grinding units and then beneath a series of polishing uni-ts (not shown), The tables I0 maybe be driven in any desired manner such as by means of suitable dr'ive pinions engaging the rack bars -I 2l2- upon the under side of tables I0. As pointed outa-bo've; the glass sheets to be surfaoed'are secured upon the tops of the tables In by a relativelyth-in layer of plaster and that after the glass has been surfaced and removed from the tables, 'itis necessary that the old plaster be cleaned off before anew layer is applied. The apparatus herein provided for removing the layer of oldplastenwhich is shown at a, includes a hollow supporting cross beam [3 arranged transversely .above the tables- I!) and supported at one end upon rollers l4 carried by a fixed guide 15 and'at its opposite end upona rocker It. The cleaning apparatus also embodies a plurality of rotary cleaning heads 1"! arranged side by side transversely'of 'the tables, each-head being secured to the lowerend of a'vertical shaft I8 which extends upwardly through the cross beam 13 and is journaled in bearings carried thereby. The three cleaning heads ll may .be driven from a single 'motor 1'9. mounted upon cross beam l3, with the shaft 20 thereof carrying a plurality of worms,one for .each cleaning head, and adaptedto mesh with wormgears keye-dto the Vertical shafts l8. Suitable means (not shown) mayalso be provided for moving the'shafts l8 vertically to effect'the raising andlowering of the cleaning heads 11. fl.

1 Although the cross beam 13 may bestationary, it is herein illustratedas': being mounted for reciprocatory movement transversely of the tables ID. The mechanism for effecting this transverse reciprocatory movement may comprise an electric motor 22 connected to drive a suitably mounted horizontal shaft 23 arranged parallel with but below and to one side of the tables said shaft carrying an eccentric 24 connected with the rocker l6 by means of a pitman rod 25. The rocker I6 is in the form of a vertically arranged sector secured at its lower end on a suitably mounted shaft 26 and the upper end of which is provided with gear teeth 21 meshing with corresponding teeth 28 on the cross beam l3. The operating movement of the rocker l6 will impart a horizontal reciprocatory movement to the cross beam I3 and thus to the cleaning heads carried thereby.

Each cleaning head comprisesan annular hub 29 keyed to the lower end of the respective shaft I8 and provided with the oppositely extending tapered arms 30 and 3| which carry at their outer ends the plaster removing units 32 and 33. Each of these units comprises a horizontal channel member 34 arranged beneath the respective arm 30 or 3| and rigidly secured thereto by bolts or the like 35. Formed integral with the under surface of the channel member 34, intermediate the ends thereof, is a depending bracket plate 361 which may be strengthened by ribs 31. Removably secured to the under surface of the channel member 34 at the outer end thereof is a Vertical retaining plate 38 arranged substantially parallel with, but being relatively narrower than bracket plate 36 as best shown in Fig. 3. The retaining plate 38 has welded or otherwise suitably secured thereto an angle bracket 38 which is fastened to the channel member 34 by bolts or the like 40.

Arranged between and carried by the plates 36 and 38 is a block 4| adapted to carry the abrading elements 42 which consist of sections of wire cable composed of individual strands of wire twisted together. The block 4| is made up of three substantially parallel clamping plates 43, 44, and 45 secured together by bolts 46. The opposing faces of the clamping plates 43, 44, and 45 are provided with semi-circular mating channels or grooves which cooperate to provide openings 41 passing vertically through the block and in which the abrading elements 42 are mounted. The bolts 46 pass transversely through all three plates 43, 44, and 45 and have threaded upon their ends nuts 48 for drawing the said plates together to firmly clamp the abrading elements therebetween.

The middle clamping plate 45 of block 4| is provided at its opposite ends with trunnions 49 and which are adapted to be received within openings in the plates 36 and 38 respectively. The trunnion 50 is also adapted to project beyond plate 38 and is threaded to receive thereon a nut 5|, by means of which the block is rigidly secured in place.

As brought out above, the cleaning action of abrading elements of the type herein disclosed has been found to be very satisfactory. Old worn-out cable will serve just as well for this purpose as new cable, so that the cost of renewing the abrading elements is relatively small. However, it has been found that the cable tends to wear away quite rapidly which is largely due to the tendency of the individual strands of wire to spread apart and be broken upon rotation of the cleaning heads. According to the present invention, this objection is effectually overcome and the life of the cable sections greatly increased by the employment of sleeves 52 which are slipped over the opposite ends of each cable section. These sleeves may be of any suitable material, such as rubber, rubber composition or the like. In fact, sections of old ordinary rubber hose may be used, so that the cost thereof is relatively small.

As shown in Fig. 6 one of the sleeves 52 is slipped over each end of each cable section 42 and the sleeves are spaced from one another so that they are not engaged by the clamping plates 43, 44, and 45. It has been found in actual use that these sleeves serve to effectively prevent spreading of the individual strands of wire and by preventing such spreading, not only greatly increase the life of the cables, but also the abrading action thereof. In other Words, the sleeves act to keep the cutting points of the strands of wire in engagement with the plaster. When the sleeves are first applied, the outer ends thereof may be disposed slightly inwardly of the ends of the cable sections as in Fig. 6, but after the cable sections become worn the sleeves will gradually wear away therewith as indicated in Fig. 7. The presence of the sleeves, however, in no way interferes with the abrading action of the cable sections. After one end of the abrading elements has been worn down relatively close to the block 4|, the block is removed and turned upside down, thereby permitting most of each cable section to be used. The cleaning heads I! are adapted to be gradually lowered as the cables wear away.

In Figs. 8 and 9 is illustrated a slightly modified type of cleaning head I'm which may be substituted for the cleaning heads above described. The cleaning head l'la also comprises a hub 53 fixed to the lower end of vertical shaft l8 and provided with the outwardly projecting horizontal arms 54 and 55. Carried upon the under side of the arms 54 and 55 are the spaced parallel supportingmembers 56 and 51 secured to said arms by bolts or the like 58. Carried atthe opposite ends of the supporting members 56 and 51 are the abrading units 59 and 60.

Each abrading unit 59 and 60 comprises a block made up of the three parallel clamping plates 6|, 62, and'63 secured together by bolts 64 and adapted to carry the abrading elements 65 in the same manner as shown in Fig. 5. The bolts 64 also pass through a vertical plate 66 carried at the corresponding ends of the supportmg members 56 and 51 and have threaded upon their inner ends nuts 61. The abrading elements 65 also consist of sections of Wire cable and slipped over the opposite ends of each cable section are the sleeves 68.

As illustrated in Fig. 8, the blocks 59 and 60 carrying the abrading elements 65 are not arranged at-right angles to the supporting members 56 and 51 but instead extend at an angle with respect thereto. In other words, the rectangular blocks 59 and 60 extend diagonally of the path of rotation thereof, with the inner end of each block being arranged forwardly of the outer end thereof. Due to this arrangement, when the cleaning head |1a is rotated in the direction indicated by the arrow, the abrading elements will tend to throw the plaster loosened from the table outwardly and away from the cleaning head. The blocks 59 and 60 can also be readily removed and turned upside down so that most of each cable section can be used.

It is to be understood that the form of the invention herewith shown and described is to be taken as the preferred embodiment of the same,

and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

I claim:

1. Apparatus for cleaning plaster from plate glass surfacing tables, comprising a support mounted for rotation about a vertical axis, a block carried by said support and including a plurality of substantially parallel clamping plates secured together, means associated with said block and support to permit inversion of the block on the support, and abrading elements consisting of sections of Wire cable vertically clamped between said clamping plates and projecting above and beneath the same.

2. Apparatus for cleaning plaster from plate glass surfacing tables, comprising a support mounted for rotation about a vertical axis, a block carried by said support and including a plurality of substantially parallel clamping plates secured together and provided with semi-circular mating grooves which cooperate to form openings passing vertically through said block, means associated with said block and support to permit inversion of the block on the support, and abrading elements consisting of sections of wire cable vertically clamped within the openings formed between said clamping plates and projecting above and beneath the same.

3. Apparatus for cleaning plaster from plate glass surfacing tables, comprising a support mounted for rotation about a vertical axis, an invertible block provided with oppositely projecting trunnions mounted in said support, and abrading elements consisting of sections of wire cable vertically carried by said block and projecting above and beneath the same.

4. Apparatus for cleaning plaster from plate glass surfacing tables, comprising a support mounted for rotation about a vertical axis, an invertible block including a plurality of substantially parallel clamping plates secured together and provided with semi-circular mating grooves which cooperates to form openings passing vertically through said block, one of said plates be ing provided with oppositely projecting trunnions mounted in said support, and abrading elements consisting of sections of wire cable vertically clamped within the openings formed between said clamping plates and projecting above and beneath the same.

5. Apparatus for cleaning plaster from plate glass surfacing tables, comprising a support mouted for rotation about a vertical axis, a substantially rectangular invertible block carried by said support, and abrading elements consisting of sections of wire cable vertically carried by said block and projecting above and beneath the same, said rectangular block extending diagonally of the path of rotation of said support and the inner end of the said block being arranged forwardly of the outer end thereof whereby upon rotation of said support the abrading elements will tend to throw the plaster loosened from the table outwardly and away from the cleaning apparatus.

6. Apparatus for cleaning plaster from plate glass surfacing tables, comprising a support mounted for rotation about a vertical axis, a substantially rectangular invertible block carried by said support including a plurality of substantially parallel clamping plates secured together and provided with semi-circular mating grooves which cooperate to form openings passing vertically through said block, and abrading elements consisting of sections of wire cable vertically clamped within the openings formed between said clamping plates and projecting above and beneath the same, said rectangular block extending diagonally of the path of rotation of said support and the inner end of the said block being arranged forwardly of the outer end thereof whereby upon rotation of said support the abrading elements will tend to throw the plaster loosened from the table outwardly and away from the cleaning apparatus.

JAMES G. HAWORTH. 

